The acute in vitro action of ACTH and corticosterone individually and in combination were determined in the B-16 melanoma grown in vivo. ACTH elevated levels 10-fold while tyrosinase activity generally was depressed. Corticosterone depressed cAMP levels and tyrosinase activity. ACTH in the presence
Interaction of ACTH, corticosterone and cyclic nucleotides in harding-passey melanoma malanogenesis
โ Scribed by Joel Abramowitz; Walter Chavin
- Publisher
- Springer-Verlag
- Year
- 1978
- Tongue
- English
- Weight
- 425 KB
- Volume
- 261
- Category
- Article
- ISSN
- 0340-3696
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โฆ Synopsis
The acute in vitro action ofadrenocorticotropin (ACTH) and corticosterone alone and in combination were determined in the Harding-Passey (HP) melanoma grown in vivo. Hormone treated melanoma dice (5-240 rain) were analyzed for tyrosinase activity, cyclic AMP (cAMP) and cyclic GMP (cGMP). ACTH elevated cAMP and cGMP levels 20-and 13-fold, respectively, in the HP melanoma. However, these large increases in cyclic nucleotide levels were accompanied by only a 49 % increase in tyrosinase activity. Corticosterone elicited a similar response. ACTH plus corticosterone produced an early cAMP and cGMP peak followed by depression. ACTH plus corticosterone stimulated tyrosinase activity coincident with the early cyclic nucleotide peak followed by a drop in tyrosinase activity which was subsequently elevated. The results indicate that neither cAMP nor cGMP are the sole modulators of tyrosinase activity and suggest the interaction of ACTH, corticosterone and cyclic nucleotides in the regulation of melanoma tyrosinase activity.
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